1. Field of the Invention
The present invention relates to weatherstripping for windows and in particular to a snap-fit weatherstripping for parting stops which is easy to install and remove so that the window may be custom fit with the required depth of insulation.
2. Description of the Prior Art
When installing new window sashes in old frames, the sash often fits loosely, allowing air to pass around the sash where the sash meets the parting stop, the vertical protruding element on each side of the window frame forming the center separation between the two tracks of the two vertical sliding sashes. Replacement of the pile weatherstripping on the parting stop with a deeper pile is often required to prevent the air flow around the sashes. With most pile weatherstripping, the window frame must be disassembled and the entire sash assembly must be removed including the inside stop molding. The lower sash and parting stop must be removed. Then the old T-shaped weatherstripping must be removed from the U-shaped slot by sliding the weatherstripping out of the slot from the bottom or top of the parting stop. Since there is one pile weatherstrip on each side of the parting stop, running the length of the parting stop, sliding the two weatherstrips out of the parting stop may take considerable time and effort. The new T-shaped nylon weatherstripping would then be installed by sliding it into the slot. This sliding installation the length of the parting stop may also be a tedious operation. The entire process of disassembly, removal, insertion, and reassembly costs time and money.
Another problem with the prior art is that the weatherstrip runs the length of the parting stop on both sides of the parting stop, so that both sashes are always in full contact with the weatherstrip whether the sashes are open or closed. Naturally in the closed position contact of the sash with the weatherstrip is desirable to keep the air from passing around the sash. However, when opening the sash contact with the weatherstrip interferes with the sliding, making the sash difficult to move and causing possible damage to the weatherstrip. With the window sash in the open position allowing the air to pour into the room, there is no point in trying to prevent the air from passing around the edges of the sash. Furthermore, having the weatherstrip exposed for half its length with the window closed is unsightly, detracting from the appearance of the house and exposing the weatherstrip to the elements and causing fast deterioration of the weatherstrip due to sun and moisture and temperature extremes.
Prior art U.S. Pat. No. 4,604,831, issued Aug. 12, 1986 to Tunmicliffe et al., claims sliding sash windows with T-shaped pile weatherstripping held in plastic U-shaped slots running along the length of each side of the parting stop (called parting bead 14 and 20 in the patent) shown in FIGS. 2, 3, 7, and 8. The weatherstripping must slide into and out of the slot with the inherent difficulties of having to disassemble the window frame and remove the parting stop in order to change the weatherstrip costing much time and energy and frustration with the tight friction fit in the long slot. The rigid barbed pile carrier 27 of FIGS. 4, 5C, and 6 requires that the pile carrier be installed in the T-shaped groove of the window frame and the pile weatherstrip 34 and 48 be inserted into and removed from the pile carrier by sliding the pile weatherstrip the length of the slot in the pile carrier, similar to the tedious process of FIGS. 2 and 3.
Prior art U.S. Pat. No. 3,224,047, issued Dec. 21, 1965 to Horton, indicates a T-shaped insertable pile weatherstripping having a metal hooked edge along the bottom with pointed protrusions formed in the edge for engaging the side of the groove in which it is inserted. The metal points 22 of the insertable portion would make the weatherstrip difficult to remove as the points would bite into the side of the slot.
U.S. Pat. No. 4,510,715, issued Apr. 16, 1985 to Giguere, describes a square-cornered Y-shaped composite weather strip for windows and doors having a stiff T-shaped base with rigid ribs on the long insertion portion for a tight friction fit in a slot of the frame or sash,. and two spaced apart flexible wings protruding away from the base rather than nylon pile. The wings contact the opposing surface and trap air between the wings for insulation. The wings would seem to cause too much friction to inhibit the movement of the window sash and the rubberized material would deteriorate quickly due to exposure to the weather. The hard ribs on the insertion portion would require hammering or other strong force to insert the weatherstrip and it would be difficult to remove.
A primary object of the present invention is to provide a custom fit changeable pile weatherstrip for windows which is replaceable in different heights of pile to accommodate variations in air space due to aging of the frame and sash and also to provide the proper air seal for replacement window sashes which may vary slightly from the width of the sashes being removed.
Another object of the present invention is to provide a window weatherstrip which is easy to insert and easy to remove with the window frame fully intact, not requiring disassembly of the window frame, so that the weatherstrip is easily replaced when it becomes worn with use or damaged by overpainting, or as changes occur in the fit of the sashes in the window frame due to shrinkage or expansion of the wood or wear.
An additional object of the present invention is to provide a weatherstrip on a parting stop with the weatherstrip positioned only on each side of the parting strip adjacent to the closed window sash, leaving the parting stop without weatherstrip on the portion adjacent to the open window sash for most efficient operation in sliding the sashes and providing longer life for the weatherstrip which is concealed by the closed sash thereby also rendering the window more attractive without being able to see the weatherstrip with the sashes in the closed positions, especially important in restorations, and requiring only half the material to cut the cost in half.
One more object of the present invention is to provide a weatherstrip with a soft barbed insertion portion for ease of installation with a compression fit and ease of removal by pulling on the weatherstrip to release the compression, and providing a tighter fit due to the insertion portion conforming to the shape of the groove in which it is inserted, thereby providing a better air barrier.
An added object of the present invention is to provide a replacement parting stop for sliding sash windows fabricated preferably of a synthetic molded or extruded material with a groove near the outside edge of the parting stop running halfway down the parting stop on one side equal to the height of one sash and running halfway down the parting stop on an alternate end of the parting stop on the other side of the parting stop, equal to the height of the other sash. The grooves are shaped to receive the flexible barbed insertion portion of the weatherstrip with an air-tight compression fit and the synthetic material has a texture conducive to creating a friction bond with the insertion portion to prevent slippage of the weatherstrip in the groove.
In brief, a parting stop, preferably of synthetic molded or extruded material, is provided with alternating longitudinal grooves on each side the length of the window sash on that respective side. The old parting stop is removed and the new one installed by conventional means. Any of a variety of pile weatherstrips having different heights of pile and a pliable barbed insertion portion is pressed into the groove with an airtight compression fit on each side the height of the sash on that respective side. Thereafter the pile weatherstrip may be easily removed by pulling it out of the grooves with the parting stop in place in the window frame and easily replaced by pressing a new length of weatherstrip of the desired pile height into the grooves. The same pile weatherstrip could be used to restrict airflow at other locations around the window.
An advantage of the present invention is that the weatherstrip could, if desired, be easily removed and inserted without the use of tools.
Another advantage of the present invention is that the pile weatherstrip could be easily exchanged for another of a different pile height for a custom fit or different weatherstrip type as desired.
An additional advantage of the present invention is that having no exposed pile with the sashes closed creates an attractive appearance, especially important in restoration work.
One more advantage of the present invention is that it requires only half of the length of pile weatherstrip normally used on parting stops, thereby saving considerably in costs of material and labor.